Parkinson’s disease is a slowly developing degenerative brain disease. It is classified as a “movement disorder” because the damage it does to your brain affects your ability to move parts of your body when you want (or don’t want) them to move.
The disease was named after the doctor, James Parkinson, who detailed the first definitive and descriptive instance of it. In the early 1800s, Parkinson published “An Essay on the Shaking Palsy,” which described a new medical condition as “paralysis agitans,” where he laid out some of the disease’s main qualities. These symptoms included “a slight sense of weakness” and “a proneness to trembling in some certain part” of the body, like your head, arms, or hands. He defined the disease as follows:
“Involuntary tremulous motion, with lessened muscular power, in parts not in action and even when supported; with a propensity to bend the trunk forwards, and to pass from a walking to a running pace: the senses and intellects being uninjured.”
The disease was first generalized as “palsy,” because the main symptoms of the disease include shaking (tremors) and, later on, paralysis—both of which generally make up a palsy diagnosis. Parkinson made the distinction between general palsy and this new disease, as he identified patients who were having tremors while resting and not trying to use the muscles that were shaking, rather than the shaking occurring while the muscles were in use. Eventually, the disease would bear the namesake of its first in-depth descriptor.